The invention is in the field of toy guns and concerns toy guns which use rubber bands to fire projectiles.
Zip guns are known which use a rubber band mounted on a gun housing to carry a firing pin against a loaded cartridge. The rubber band is stretched away from the firing rim of the cartridge so that the firing pin is placed under an elastic tension directed toward the cartridge firing rim. The cartridge is held in position in a barrel mounted on the gun housing such that the firing rim of the cartridge faces the cocked firing pin, while the projectile in the cartridge is directed through the barrel toward the muzzle of the gun. When the rubber band is released, the firing pin is accelerated by the collapsing rubber band against the firing rim of the cartridge. The cartridge is activated when the firing pin strikes the primer in the firing rim; the cartridge charge explodes and the expanding gases generated by the explosion accelerate the cartridge projectile through the barrel toward the muzzle.
Toy guns which shoot projectiles such as pellets, B-B's, or round shot characteristically use pneumatic means to pump a charge of compressed air which is released by a trigger and directed through a pneumatic tube against a single shot held in the barrel of the air gun. The expansion of the compressed air against the shot accelerates it out of the barrel toward the muzzle. As is known, the pneumatic mechanisms of air guns and other compressed gas-powered weapons are subject to corrosion and leakage, both of which cause the gun to eventually lose its firepower. Replacement of the pneumatic mechanism is impractical and expensive. Therefore, when a pneumatic gun loses its potency, the gun usually is discarded and a new one obtained.
Typically, the non-pneumatic moving parts of an air gun outlast the pneumatic parts of the gun's firing mechanism. Therefore, there is a clear,,need to provide a non-pneumatic firing mechanism which both wears as long as the other non-pneumatic parts of a pellet gun and which can be easily and inexpensively replaced when worn.